Compilare: user.cpp: In function ‘void AddLetter(int)’: user.cpp:75:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(tree[node].next[letter]!=0){ ^ user.cpp:76:38: warning: array subscript has type ‘char’ [-Wchar-subscripts] suffix=tree[node].next[letter]; ^ user.cpp:83:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] tree[node].next[letter]=nodes; ^ user.cpp:93:52: warning: array subscript has type ‘char’ [-Wchar-subscripts] tree[nodes].fail=tree[node].next[letter]; ^ user.cpp: In function ‘int main()’: user.cpp:203:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (j < pal.size() && pal[j].first.first <= i) { ~~^~~~~~~~~~~~ user.cpp: In function ‘char Advance()’: user.cpp:25:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, 1, SIZE, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:183:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fft.in", "r", stdin); ^ user.cpp:184:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fft.out", "w", stdout); ^ user.cpp:185:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld\n%s", &b, &m, s + 1); ^ user.cpp:209:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &q); ^ user.cpp:213:46: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%d%d", &x, &y, &a, &b); ^